The present invention relates to optical recording media adapted for storing information. In particular, the invention relates to a dye-in-polymer coating for use in an optical recording media.
Optical recording media are used for high density information storage. In an optical recording system, typically an optical disc is rotated at a high speed and a laser is used for both reading and writing information. A surface of the optical disc has optical properties which can be changed in order to store information.
Organic optical media have recently been used for fabricating Write-Once-Read-Many (WORM) optical discs. Typically, information is recorded by producing pits in a dye covered surface of the storage medium. In general, an organic storage medium using pits to store information can either be vapor-deposited or spin coated onto a substrate. Organic dye is sometimes spin coated along with a polymer matrix, often called a "dye-in-polymer (DIP)" system. However, an organic dye can be spin coated onto substrates alone by using a suitable solvent. This is referred to as a single dye system.
A single dye system has the advantage of simplicity, but suffers from lack of precise control of the thickness of the medium during the spin coating deposition process. The thickness of the recording layer significantly influences the read-write characteristics of the disc, especially the carrier-to-noise ratio. Therefore, it is important to be able to control the thicknesses of a recording layer.